Готові списки джерел за темами / Planktic

Добірка наукової літератури з теми "Planktic"

Автор: Grafiati
Опубліковано: 10 грудня 2022
Оновлено: 10 березня 2023

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Статті в журналах з теми "Planktic"

1

Emiliani, Cesare. "Planktic/planktonic, nektic/nektonic, benthic/benthonic." Journal of Paleontology 65, no. 2 (March 1991): 329. http://dx.doi.org/10.1017/s0022336000020576.

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2

Lam, Adriane R., and R. Mark Leckie. "Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean." Micropaleontology 66, no. 3 (2020): 177–268. http://dx.doi.org/10.47894/mpal.66.3.01.

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Анотація:
Patterns of diversity in the modern planktic foraminifera indicate a latitudinal diversity gradient (LDG), which peaks in the mid-latitude regions. Plankton distributional patterns are oftenmost strongly associated with temperature and are expected to change in response to expanded tropical water masses. Defining the underlying causes of climatic and oceanographic processes, however, requires detailed, local-scale diversity curves and evolutionary metrics, as well as solid taxonomic concepts of planktic foraminifera, to test the oceanographic processes driving evolution ofmarine plankton. Currently, diversity estimates for the planktic foraminifera are mainly based on global datasets skewed towards tropical to subtropical sites and conducted at coarse resolutions that hamper investigations of evolutionary processes, especially for short-lived climate perturbations. Here, we present 10-kyr resolution diversity curves and 25-kyr resolution local first appearance and extirpation rates of planktic foraminifera for four Ocean Drilling Program sites that extend from the temperate northern edge of the modern-day position of the Kuroshio Current Extension (KCE) to the tropics. We provide an updated taxonomic review of late Neogene planktic foraminiferal species from within the influence of the KCE. These data allow for investigations of the western Pacific LDG and patterns of evolution through the late Neogene in response to tectonic and climate events. Our results indicate that a mid-latitude diversity peak has been prominent in the western Pacific since at least 12.1Ma, with highest diversity generally on the northern edge of the KCE. These data contradict previous studies indicating highest diversity is located +/- 20 degrees, as our data reveal highest diversity for the planktic foraminifera at +/- 35 degrees N likely due to strong seasonality. Development of the modern North Pacific gyre system due to closure of the Central American Seaway and constriction of the Indonesian Throughflow increased the LDG between the tropics and the northernmost site, likely in response to KCE intensification. Diversity was only slightly affected during the mid-Piacenzian Warm Period (approx. 3.2-2.9Ma),with diversity gradients between the equatorial site and southernmost mid-latitude sites becoming similar, perhaps indicating a weaker thermal gradient developing in the northwest Pacific as the KCE and warmer waters were displaced northwards.With intensification of Northern Hemisphere glaciation came a decrease in diversity at the northernmost site, hypothesized to be caused by subtropical gyre constriction and southward displacement of subpolar surface waters. The beginning of the mid-Pleistocene transition marks an increase in diversity gradients, especially between the northernmost and tropical sites. A detailed taxonomic evaluation of planktic foraminiferal species has led to synonymization of what we consider regional morphological variants, as well as revised taxonomic concepts of key subtropical to temperate late Neogene planktic foraminifera. Scanning electron micrographs capture the morphological variability within a species concept for the first time in great detail for this part of the world ocean. These data and updated taxonomic concepts provide a framework for future studies to link evolutionary patterns with high-resolution geochemical and sedimentological data to further interpret localized drivers of diversification in the planktic foraminifera.
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3

Tapia, Raúl, Sze Ling Ho, Hui-Yu Wang, Jeroen Groeneveld, and Mahyar Mohtadi. "Contrasting vertical distributions of recent planktic foraminifera off Indonesia during the southeast monsoon: implications for paleoceanographic reconstructions." Biogeosciences 19, no. 13 (July 7, 2022): 3185–208. http://dx.doi.org/10.5194/bg-19-3185-2022.

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Abstract. Planktic foraminifera are widely used in paleoceanographic and paleoclimatic studies. The accuracy of such reconstructions depends on our understanding of the organisms' ecology. Here we report on field observations of planktic foraminiferal abundances (>150 µm) from five depth intervals between 0–500 m water depth at 37 sites in the eastern tropical Indian Ocean. The total planktic foraminiferal assemblage here comprises 29 morphospecies, with 11 morphospecies accounting for 90 % of the total assemblage. Both species composition and dominance in the net samples are broadly consistent with the published data from the corresponding surface sediments. The abundance and vertical distribution of planktic foraminifera are low offshore western Sumatra and increase towards offshore southern Java and the Lesser Sunda Islands (LSI). Average living depth of Trilobatus trilobus, Globigerinoides ruber, and Globigerina bulloides increases eastward, while that of Neogloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia menardii remains constant. We interpret the overall zonal and vertical distribution patterns in planktic foraminiferal abundances as a response to the contrasting upper-water-column conditions during the southeast monsoon, i.e., oligotrophic and stratified offshore Sumatra (non-upwelling) vs. eutrophic and well mixed offshore Java–LSI (upwelling). Overall, the inferred habitat depths of selected planktic foraminifera species show a good agreement with those from sediment trap samples and from surface sediments off Sumatra, but not with those from surface sediments off Java–LSI. The discrepancy might stem from the different temporal coverage of these sample types. Our findings highlight the need to consider how foraminiferal assemblages and ecology vary on shorter timescales, i.e., from “snapshots” of the water column captured by a plankton net to seasonal and interannual variability as recorded in sediment traps, and how these changes are transferred and preserved in deep-sea sediments.
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4

Singh, Ashutosh K., and Devesh K. Sinha. "Plio-Pleistocene Planktic Foraminiferal Biochronology of ODP Site 762B, Exmouth Plateau, Southeast Indian Ocean." Journal of Foraminiferal Research 52, no. 4 (October 1, 2022): 248–63. http://dx.doi.org/10.2113/gsjfr.52.4.248.

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ABSTRACT The Indonesian Throughflow region connects the tropical Pacific Ocean with the eastern Indian Ocean, and variability of the Throughflow during the Plio-Pleistocene has been related to major climate shifts at the global level. Planktic foraminiferal biostratigraphy integrated with magnetochronology provides a robust time framework for assigning age control to major paleoceanographic events. Understanding of the coupled histories of the El Niño Southern Oscillation, Western Pacific Warm Pool, Indonesian Throughflow, and the eastern Indian Ocean has greatly benefitted from the chronological framework provided by planktic foraminiferal biostratigraphies from these regions. Ocean Drilling Program (ODP) Hole 762 lies under the influence of the Leeuwin Current, originating from the Indonesian Throughflow. Multiproxy data have been collected from Hole 762B and other nearby sites for paleoceanographic interpretation. However, a detailed planktic foraminiferal biostratigraphy integrated with magnetochronology is not available from this site. We provide here the sequential order of planktic foraminiferal First Occurrence (FO) and Last Occurrence (LO) events, which allowed us to divide the examined section into seven biostratigraphic zones. The biostratigraphy was integrated with magnetostratigraphy using revised ages of magnetochrons, which yielded biochronological age estimates for planktic foraminiferal events. A major planktonic faunal turnover between 3.4 and 2.7 Ma is probably related to the onset of the Northern Hemisphere glaciation and related changes in the Indonesian Throughflow. We have compared our numerical age estimates with published ages from other parts of the world. The diachronism observed probably is related to the local oceanographic setting of ODP Hole 762B, which has been alternatively influenced by changing strengths of the warm Leeuwin Current and the cold west Australian Current. The biochronology established here will be useful for correlating paleoceanographic events in the region.
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5

Schiebel, Ralf, and Christoph Hemleben. "Modern planktic foraminifera." Paläontologische Zeitschrift 79, no. 1 (March 2005): 135–48. http://dx.doi.org/10.1007/bf03021758.

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6

Emiliani, Cesare. "Planktic et al." Marine Micropaleontology 18, no. 1-2 (November 1991): 3. http://dx.doi.org/10.1016/0377-8398(91)90003-o.

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7

D'Hondt, Steven, and James C. Zachos. "Cretaceous foraminifera and the evolutionary history of planktic photosymbiosis." Paleobiology 24, no. 4 (1998): 512–23. http://dx.doi.org/10.1017/s0094837300020133.

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Ecotypic correlations between stable isotopic signals and skeletal size indicate that some Late Cretaceous serial planktic foraminifera were strongly photosymbiotic. In contrast, coeval trochospiral planktic foraminifera do not exhibit the isotope/size signatures that typify strongly photosymbiotic species. Comparison to Cenozoic taxa demonstrates that photosymbiosis has recurred throughout planktic foraminiferal history and has evolved independently in superfamilies characterized by very different gross skeletal morphologies. The historical contingency of that evolution is illustrated by the consequences of the Cretaceous/Paleogene mass extinction, which terminated the Cretaceous lineages of photosymbiotic planktic foraminifera but did not permanently extinguish photosymbiont reliance by planktic foraminifera.
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8

Lam, Adriane R., Martin P. Crundwell, R. Mark Leckie, James Albanese, and Jacob P. Uzel. "Diachroneity Rules the Mid-Latitudes: A Test Case Using Late Neogene Planktic Foraminifera across the Western Pacific." Geosciences 12, no. 5 (April 26, 2022): 190. http://dx.doi.org/10.3390/geosciences12050190.

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Planktic foraminifera are commonly used for first-order age control in deep-sea sediments from low-latitude regions based on a robust tropical–subtropical zonation scheme. Although multiple Neogene planktic foraminiferal biostratigraphic zonations for mid-latitude regions exist, quantification of diachroneity for the species used as datums to test paleobiogeographic patterns of origination and dispersal is lacking. Here, we update the age models for seven southwest-Pacific deep-sea sites using calcareous nannofossil and bolboform biostratigraphy and magnetostratigraphy, and use 11 sites between 37.9° N and 40.6° S in the western Pacific to correlate existing planktic foraminiferal biozonations and quantify the diachroneity of species used as datums. For the first time, northwest and southwest Pacific biozones are correlated and compared to the global tropical planktic foraminiferal biozonation. We find a high degree of diachroneity in the western Pacific, within and between the northwest and southwest regions, and between the western Pacific and the tropical zonation. Importantly, some datums that are found to be diachronous between regions have reduced diachroneity within regions. Much work remains to refine regional planktic foraminiferal biozonations and more fully understand diachroneity between the tropics and mid-latitudes. This study indicates that diachroneity is the rule for Late Neogene planktic foraminifera, rather than the exception, in mid-latitude regions.
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9

Lam, Adriane R., Martin P. Crundwell, R. Mark Leckie, James Albanese, and Jacob P. Uzel. "Diachroneity Rules the Mid-Latitudes: A Test Case Using Late Neogene Planktic Foraminifera across the Western Pacific." Geosciences 12, no. 5 (April 26, 2022): 190. http://dx.doi.org/10.3390/geosciences12050190.

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Анотація:
Planktic foraminifera are commonly used for first-order age control in deep-sea sediments from low-latitude regions based on a robust tropical–subtropical zonation scheme. Although multiple Neogene planktic foraminiferal biostratigraphic zonations for mid-latitude regions exist, quantification of diachroneity for the species used as datums to test paleobiogeographic patterns of origination and dispersal is lacking. Here, we update the age models for seven southwest-Pacific deep-sea sites using calcareous nannofossil and bolboform biostratigraphy and magnetostratigraphy, and use 11 sites between 37.9° N and 40.6° S in the western Pacific to correlate existing planktic foraminiferal biozonations and quantify the diachroneity of species used as datums. For the first time, northwest and southwest Pacific biozones are correlated and compared to the global tropical planktic foraminiferal biozonation. We find a high degree of diachroneity in the western Pacific, within and between the northwest and southwest regions, and between the western Pacific and the tropical zonation. Importantly, some datums that are found to be diachronous between regions have reduced diachroneity within regions. Much work remains to refine regional planktic foraminiferal biozonations and more fully understand diachroneity between the tropics and mid-latitudes. This study indicates that diachroneity is the rule for Late Neogene planktic foraminifera, rather than the exception, in mid-latitude regions.
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10

Sarnthein, Michael, Sven Balmer, Pieter M. Grootes, and Manfred Mudelsee. "Planktic and Benthic 14C Reservoir Ages for Three Ocean Basins, Calibrated by a Suite of 14C Plateaus in the Glacial-to-Deglacial Suigetsu Atmospheric 14C Record." Radiocarbon 57, no. 1 (2015): 129–51. http://dx.doi.org/10.2458/azu_rc.57.17916.

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This article presents a compilation of planktic and benthic 14C reservoir ages for the Last Glacial Maximum (LGM) and early deglacial from 11 key sites of global ocean circulation in the Atlantic and Indo-Pacific Ocean. The ages were obtained by 14C plateau tuning, a robust technique to derive both an absolute chronology for marine sediment records and a high-resolution record of changing reservoir/ventilation ages (Δ14C values) for surface and deep waters by comparing the suite of planktic 14C plateaus of a sediment record with that of the atmospheric 14C record. Results published thus far have used as atmospheric 14C reference U/Th-dated corals, the Cariaco planktic record, and speleothems. We have now used the varve-counted atmospheric 14C record of Lake Suigetsu terrestrial macrofossils to recalibrate the boundary ages and reservoir ages of the seven published records directly to an atmospheric 14C record. In addition, the results for four new cores and further planktic results for four published records are given. Main conclusions from the new compilation are the following: (1) The Suigetsu atmospheric 14C record on its varve-counted timescale reflects all 14C plateaus, their internal structures, and relative length previously identified, but implies a rise in the average 14C plateau age by 200–700 14C yr during the LGM and early deglacial times. (2) Based on different 14C ages of coeval atmospheric and planktic 14C plateaus, marine surface water Δ14C may have temporarily dropped to an equivalent of ∼0 yr in low-latitude lagoon waters, but reached >2500 14C yr both in stratified subpolar waters and in upwelled waters such as in the South China Sea. These values differ significantly from a widely assumed constant global planktic Δ14C value of 400 yr. (3) Suites of deglacial planktic Δ14C values are closely reproducible in 14C records measured at neighboring core sites. (4) Apparent deep-water 14C ventilation ages (equivalents of benthic Δ14C), deduced from the sum of planktic Δ14C and coeval benthic-planktic 14C differences, vary from 500 up to >5000 yr in LGM and deglacial ocean basins.
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Дисертації з теми "Planktic"

1

Caromel, Aude Genevieve Marcelle. "Form and function in planktic foraminifera." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.628998.

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Planktic foraminiferal tests and their morphology have been the subject of extensive study for biostratigraphy and palaeoenvironmental reconstructions. Iterative evolution of morphological designs and correlations between morphology and environmental parameters suggest either fundamental intrinsic constraints on form , or a functional control, or both. Yet the adaptive significance of the test morphologies in terms of these constraints has never been rigorously explored, and is the focus of this thesis. The developmental and growth constraints delimiting the scope of action for evolution were determined through ontogenetic reconstructions based on SRXTM scans. Differences in growth patterns between the globigerinid and globorotalid groups imply a different potential for diversification. Different metabolic processes dominate growth at different stages of ontogeny due to changes in surface area-to-volume ratios, so mechanisms of evolution responding to environmental factors may change depending on when they occur in ontogeny. Imposed on these are constructional considerations, which were gauged through estimation of coiling patterns through ontogeny from the reconstructions. Coiling in early ontogeny is constrained across all species to maximise lateral growth. From the neanic stage, changes in coiling occur to accommodate new chamber shapes, and are modulated by the migration of the aperture. Developmental processes of evolution must therefore operate within this framework. Computational fluid dynamic simulations were used to assess the functional role of the test in adjusting settling velocity, by varying morphological and water parameters independently. The range of evolutionary options open to foraminifera is a result of trade-offs between changes in size, shape and density, and environmentally required fluctuations can easily be accommodated by the natural within-population variability. The findings of this thesis imply that, in the compromise between function and constraints acting with the environment to define adult morphology and diversification, intrinsic factors are likely to play a more important role than function in plank tic foraminifera.
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2

Beer, Christopher James. "Planktic foraminifera, ocean sediments and the palaeo-marine carbonate system." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/208361/.

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3

Schmuker, Barbara. "Recent planktic foraminifera in the Caribbean sea : distribution, ecology and taphonomy /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13559.

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4

Pados, Theodora [Verfasser]. "Recent planktic foraminifera in the Fram Strait : ecology and biogeochemistry / Theodora Pados." Kiel : Universitätsbibliothek Kiel, 2014. http://d-nb.info/1059109166/34.

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5

Rückheim, Sylvia. "The onset of planktic foraminifera in the mid-Cretaceous of the Boreal Realm." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975763350.

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6

Steel, Blair Andrew. "Molecular and palaeontological approaches to the reconstruction of neogene spinose planktic foraminiferal phylogeny." Thesis, Royal Holloway, University of London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429407.

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7

Stewart, Iain A. "The molecular evolution of planktic foraminifera and its implications for the fossil record." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/13020.

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The marine microfossils of planktic foraminifers are widely used for investigating palaeoceanographic and palaeoclimatic conditions. The objective of this project was to investigate genotypic variation within planktic foraminiferal morphospecies and the spatial distribution of genotypes in the subpolar, transitional and subtropical North Atlantic. Foraminiferal genomic DNA was extracted and the ~1000 base pair 3' terminal region of the small subunit ribosomal RNA gene was amplified using the polymerase chain reaction. Using distance-based molecular phylogenetic analysis, a neighbour-joining phylogeny was reconstructed based on 31 planktic and15 benthic previously sequenced foraminifera and extended to include 15 genotype sequences obtained from the North Atlantic during this study. Bulk plankton samples were collected for preliminary examination of genotype/morphotype relationships. The molecular phylogeny is largely consistent with the foraminiferal fossil record. It supports the suggestion that the origins of planktic foraminifers are polyphyletic, as the spinose planktic foraminifers cluster separately from the non-spinose planktic foraminifers within the phylogeny. Brachn length variation within the planktic cluster reflects large differences in evolution rate between morphospecies. Within the North Atlantic, genotypic variation has been identified within the morphospecies, Globigerina bulloides, Turborotalita quinqueloba, Globigerinella siphonifera, Globigerinella calida, Globigerinoides ruber and Neogloboquadrina pachyderma. The distribution of genotypes is complex, and it has been found that genotypes, representing a single morphospecies, often co-exist within the water column. This could be indicative of cryptic speciation, suggesting that North Atlantic planktic foraminiferal diversity is much higher than fossil record interpretations have indicated. The genotypes within G. bulloides, G. siphonifera, G. calida and T. quinqueloba have different geographic distributions within the North Atlantic. It is apparent that G. bulloides Types IIa and IIb and G. siphonifera Types IIa and IIb have extensive distributions suggesting that they are more generalist in adaptation, and tolerant to a wide range of oceanic conditions.
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8

Palmer, Denise D. "Late Holocene planktic foraminiferal assemblages from Orca Basin : effects of dissolution on faunal assemblages." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001693.

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9

D'ONOFRIO, Roberta. "Planktic foraminiferal response to the early Eocene climatic perturbations: the post-PETM hyperthermals and the EECO event." Doctoral thesis, Università degli studi di Ferrara, 2017. http://hdl.handle.net/11392/2488050.

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Анотація:
Obiettivo di questa ricerca è l’indagine di alcuni episodi di riscaldamento estremo a breve e lunga durata dell’Eocene inferiore associati a profonde variazioni del ciclo del Carbonio e condizioni paleooceanografiche: ipertermali e Early Eocene Climatic Optimum (EECO). A tal fine sono state selezionate tre successioni eoceniche di mare profondo da diversi contesti paleoceanografici: dalle basse latitudini, la sezione della Tetide centro occidentale del Terche (Italia nord orientale) e il Site Atlantico occidentale ODP 1051 (Blake Nose) dalle medie latitudini il Site Atlantico sud orientale ODP 1263 (Walvis Ridge). Questi casi-studio sono stati affrontati integrando analisi micropaleontologica e geochimica. La prima è principalmente basata sui foraminiferi planctonici, ampiamente utilizzati per studi paleoambientali poiché registrano effetti delle perturbazioni delle acque superficiali nella chimica dei gusci e nelle variazioni delle associazioni. Le indagini degli ipertermali H1 o ETM2, H2 e I1 nella sezione di Terche mostrano rilevanti cambiamenti nelle associazioni del plancton calcareo che indicano aumento di eutrofia associato a un indebolimento della stratificazione termica delle acque superficiali, sebbene le variazioni siano transitorie e più intense durante l’ETM2. Ciascun evento coincide con anomalie marnose riconducibili all’aumento della diluizione terrigena poiché gli indicatori di dissoluzione non mostrano variazioni significative. Le condizioni di perturbazione persistono anche durante la fase di recupero del ciclo del carbonio implicando tassi di ripresa più lenti per ambiente e biota. L'analisi dell’EECO nei Site atlantici rivela significativi cambiamenti nelle associazioni a foraminiferi planctonici. Il più evidente è la drastica riduzione in abbondanza e numero di specie di Morozovella e un parallelo incremento nelle abbondanze e diversificazione di Acarinina. Le possibili cause di questo turnover globale e permanente, già documentato in altre località delle basse latitudini, possono essere molteplici ed includono: temperature elevate, prolungati alti livelli di pCO2, acidificazione delle acque superficiali, perdita dei simbionti (bleaching) o competizione ecologica. Il test sui morozovellidi del Site 1051, per verificare l'ipotesi del bleaching attraverso l'analisi del segnale del δ13C, mostra evidenze di bleaching e riduzione nella dimensione dei gusci in alcune specie di Morozovella poco sopra l'evento J. Questo segnale è tuttavia transitorio ed interessa anche gli acarininidi invalidando così questa ipotesi per spiegare il calo permanente di Morozovella. Varie specie di Morozovella non recuperano la massima dimensione del guscio; ciò implica il superamento della loro soglia di optimum ecologico durante l’EECO. L’analisi della direzione di avvolgimento nei morozovellidi dei Site 1051 e 1263 evidenzia una preferenza nell’avvolgimento destrorso durante l'intervallo che precede l’EECO. Tuttavia, si osserva una prima marcata inversione verso un avvolgimento sinistrorso poco sopra il J che diviene permanente poco sopra il K/X. Incrementi temporanei delle forme sinistrorse si verificano anche durante alcuni ipertermali pre-EECO. Precedenti interpretazioni prediligono una spiegazione genetica per le inversioni dell’avvolgimento piuttosto che una risposta ecologica. Questi nuovi dati non possono convalidare o negare la prima ipotesi, ma stimolano una rinnovata considerazione della seconda. Alla base dell’EECO nel Site 1263 si registra inoltre la virtuale scomparsa dei chiloguembelinidi e la riduzione nell’abbondanza dei subbotinidi riconducibili ad una contrazione delle nicchie ecologiche dovuta all'indebolimento della stratificazione termica delle acque. Il segnale a foraminiferi planctonici sottolinea il sorprendente effetto della perturbazione di lunga durata indotta dall’EECO che si è sovrapposto ed ha prevalso sui cambiamenti effimeri legati agli ipertermali.
The main goal of this research was to investigate some extreme warming episodes characterizing the early Eocene climate and related to profound variations on the global carbon cycle and paleoceanographic conditions, the short-lived hyperthermals and the long-lasted Early Eocene Climatic Optimum (EECO). To pursue this aim three early Eocene deep-sea successions were selected from different paleoceanographic settings: the low-latitude central western Tethyan Terche section (northeastern Italy) and the western Atlantic ODP Site 1051 (Blake Nose), and the mid-latitudes southeastern Atlantic ODP Site 1263 (Walvis Ridge). These case studies were approached with integrated micropaleontological and geochemical analysis. The former is mainly based on planktic foraminifera, widely employed in the study of past environments as they record the effects of surface waters perturbations both in test chemistry and changes within the assemblages. Investigation of the three hyperthermals, H1 or ETM2, H2 and I1 at the Tethyan Terche section highlights significant changes in calcareous plankton assemblages across these events, suggesting increase in surface-water eutrophication coupled with a weakening of the upper water-column thermal stratification, although these changes were transient and more intense during the ETM2. Each event coincides with lithological anomalies interpreted as essentially linked to increased terrigenous dilution, as dissolution proxies do not display significant variations. The perturbed conditions persisted during the early CIE recovery, implying slower recovery rates for the environment and biota than for the carbon cycle. The analysis of the Atlantic sites encompassing the EECO reveals major changes in planktic foraminiferal assemblages across this perturbation mainly consisting in a permanent reduction in abundance and number of species of Morozovella paralleled by increase in abundance and diversification of Acarinina. Possible causes to explain this global and permanent overturn, previously documented in other low-latitude locations, are manifold and may include the sustained elevated temperature, prolonged high level of pCO2, surface-waters acidification, loss of photo-symbionts (bleaching) or even ecological competition. A test on Morozovella species from Site 1051 was performed to verify the bleaching hypothesis through analysis of the δ13C signal. Evidences of bleaching and test-size reduction were documented in a number of Morozovella species just above the J event. Nonetheless, the bleaching signal was transient and also involved acarininids, thus invalidating this hypothesis to explain the Morozovella permanent drop. Some Morozovella species never recover their maximum test-size implying that their ecological optimum threshold was crossed during the EECO. Analysis of the Morozovella coiling direction at Sites 1051 and 1263 highlight a dominant dextral preference for this genus during the interval preceding the EECO. However, all species show a first prominent flip to sinistral coiling starting slightly above the J event that became permanent slightly above the K/X event. Temporary switches towards sinistral coiling mode also occurred during several pre-EECO hyperthermals. Previous interpretations favour genetic explanations for coiling flips rather than ecological responses. These new data cannot validate or disprove the former idea, but should stimulate renewed thought on the latter idea. Planktic foraminiferal response to the EECO at Site 1263 also includes the virtual disappearance of the chiloguembelinids and abundance reduction of the thermocline-dweller subbotinids, interpreted as a result of ecological niches contraction probably related to weakening of the upper water-column thermal stratification. The whole planktic foraminiferal signal emphasizes the striking effect of the long-lasted EECO perturbation that superimposed and prevailed on the ephemeral changes linked to the hyperthermals.
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Soldan, D. M. "REVISION OF PALEOCENE-EOCENE PLANKTIC FORAMINIFERAL BIOSTRATIGRAPHY AND EVOLUTIONARY HISTORY OF THE GENUS IGORINA THROUGH PARSIMONY ANALYSIS." Doctoral thesis, Università degli Studi di Milano, 2011. http://hdl.handle.net/2434/152906.

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Анотація:
The evolution of planktonic foraminifera in the Paleocene-Eocene time interval is characterized by a high rate of diversification after the major extinction event observed at the Cretaceous/Paleogene boundary. The accelerated speciation rate resulted in the appearance of several new genera (i.e., Praemurica, Igorina, Morozovella, Acarinina among others) each of them identified on the basis of distinctive wall texture of the shell. Phylogenetic relationships within many genera are still poor understood including the origin and phylogeny of the genus Igorina. This group, characterized by a thick, nonspinose and incrusted wall, appears in Subzone P3a (early late Paleocene, Selandian) and disappears in Zone E9 (middle Eocene, Lutetian). To date, eight species have been assigned to the genus Igorina (I. pusilla, I. trichotrocha, I. tadjikistanensis, I. albeari, I. laevigata, I. lodoensis, I. broedermanni and I. anapetes) based on both wall texture and morphologic similarities. However, the taxonomic identification at species level is affected by several problems, mainly related to poor descriptions and illustrations of the type-material of several species. Consequently, for many years the morphological features proper of each species have been frequently misinterpreted. This study is aimed to reconstruct the phylogeny and evolution of the igorinid species throught cladistic analysis by applying the method of parsimony. To perform the study, two hundred samples have been analysed from Ocean Drilling Program (ODP) Leg 198 Hole 1209B (Shatsky Rise, Central Pacific Ocean), Leg 143 Hole 865B (Allison Guyot, Central Pacific Ocean), Leg 15 Sites 151 and 152 (Caribbean Sea) and Leg 113 Hole 690B. The biostratigraphic analysis of sub-tropical localites revealed some problems in applying the previous biostratigraphic scheme (Berggren and Pearson, 2005) mainly because some marker species 1) have been misinterpreted and/or misidentified several times in previous studies, 2) show a delayed appearance with respect to what reported from other localities, and 3) are very rare or absent in the studied samples. Species identification was mainly performed through comparison with the original descriptions and illustrations and partially follows Subbotina (1953), Blow (1979), Olsson and others (1999), Pearson and others (2006). Phylogenetic relationships of the species assigned to Igorina are determined through stratocladistic analysis by using a data matrix of 23 taxa (including key species of Acarinina), 31 morphological characters (unordered), and a stratigraphic character (ordered) mapping the first occurrence of the taxa under investigation. The morphological characters included in this analysis are based on morphometric measurements such as the angle of chambers, maximum diameter of the shell, maximum diameter of the inner whorls, angle of peripheral margin among others. The same characters were also measured on the SEM illustrations of the type species of each holotype and, hence, included in the data matrix. Some morphotypes of uncertain taxonomic identification but showing consistent morphological and wall texture features have been coded and analysed separately as morphotypes A, B, C, D, E and F to determine their ancestor-descendant relationships and evaluate their validity as discrete species. The software PAUP* (Swofford 2002) has been used to process the data and to obtain a numerical matrix with codified the selected characters, then the matrix has been processed using the heuristic search option to discover the most parsimonious trees. Results suggest that Igorina pusilla is the first representatives of the Igorina lineage and is subsequently followed by I. laevigata. I. albeari, and I. tadjikistanensis in agreement with their stratigraphic distribution. Morphotypes (C, E, F) have been included in Igorina paraspiralis (Soldan and others, in press) while Igorina morphotype A represents a single species (Igorina praecarinata Soldan and others, in press). Morphotypes B and E fall in the variability of well-know species. Moreover, the analysis provides evidence that I. trichotrocha, I. lodoensis, I. broedermanni and I. anapetes are more closely related to genus Acarinina than Igorina and clearly belong to a different lineage. A preliminary analysis of the wall texture architectures the broedermanni group has been performed to assess their ancestor-descendant relationships and to evaluate the possibility to place them in a discrete new genus.
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Книги з теми "Planktic"

1

Schiebel, Ralf, and Christoph Hemleben. Planktic Foraminifers in the Modern Ocean. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6.

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2

Berggren, William A. Biostratigraphy, phylogeny and systematics of Paleocene trochospiral planktic Foraminifera. New York, N.Y: Micropaleontology Press, 1997.

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3

Survey), PRISM Project (Geological, and Geological Survey (U.S.), eds. Pliocene planktic foraminifer census data from the North Atlantic region. [Reston, Va.]: Dept. of the Interior, U.S. Geological Survey, 1996.

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4

Foley, Kevin M. Planktic foraminifer census data from Northwind Ridge Core 5, Arctic Ocean. [Reston, Va.]: U.S. Geological Survey, 1991.

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5

Z, Poore Richard, and Geological Survey (U.S.), eds. Planktic foraminifer census data from Northwind Ridge Core 5, Arctic Ocean. [Reston, Va.]: U.S. Geological Survey, 1991.

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6

Geological Survey (U.S.), ed. Planktic foraminifer census data from sites V19-257 and RC17-44. [Reston, Va.]: Dept. of the Interior, U.S. Geological Survey, 1996.

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7

Geological Survey (U.S.), ed. Planktic foraminifer census data from sites V19-257 and RC17-44. [Reston, Va.]: Dept. of the Interior, U.S. Geological Survey, 1996.

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8

Bybell, Laurel M. Calcareous nannofossils and planktic foraminifers from Enewetak Atoll, western Pacific Ocean. Washington: U.S. G.P.O., 1991.

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9

Foley, Kevin M. Planktic foraminifer census data from Northwind Ridge Core 5, Arctic Ocean. [Reston, Va.]: U.S. Geological Survey, 1991.

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10

Geological Survey (U.S.), ed. Pliocene planktic foraminifer census data from Deep Sea Drilling Project hole 603C. [Reston, Va.]: U.S. Geological Survey, 1991.

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Частини книг з теми "Planktic"

1

Kimoto, Katsunori. "Planktic Foraminifera." In Marine Protists, 129–78. Tokyo: Springer Japan, 2015. http://dx.doi.org/10.1007/978-4-431-55130-0_7.

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2

Maletz, Jörg. "The Planktic Revolution." In Graptolite Paleobiology, 139–52. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781118515624.ch9.

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3

Schiebel, Ralf, and Christoph Hemleben. "Classification and Taxonomy of Extant Planktic Foraminifers." In Planktic Foraminifers in the Modern Ocean, 11–110. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_2.

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4

Schiebel, Ralf, and Christoph Hemleben. "Introduction." In Planktic Foraminifers in the Modern Ocean, 1–9. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_1.

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Schiebel, Ralf, and Christoph Hemleben. "Methods." In Planktic Foraminifers in the Modern Ocean, 295–343. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_10.

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6

Schiebel, Ralf, and Christoph Hemleben. "Cellular Ultrastructure." In Planktic Foraminifers in the Modern Ocean, 111–27. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_3.

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Schiebel, Ralf, and Christoph Hemleben. "Nutrition, Symbionts, and Predators." In Planktic Foraminifers in the Modern Ocean, 129–57. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_4.

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8

Schiebel, Ralf, and Christoph Hemleben. "Reproduction." In Planktic Foraminifers in the Modern Ocean, 159–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_5.

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9

Schiebel, Ralf, and Christoph Hemleben. "Ontogeny and Test Architecture." In Planktic Foraminifers in the Modern Ocean, 177–207. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_6.

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10

Schiebel, Ralf, and Christoph Hemleben. "Ecology." In Planktic Foraminifers in the Modern Ocean, 209–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-50297-6_7.

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Тези доповідей конференцій з теми "Planktic"

1

Hoogakker, Babette, Caroline Anderson, Helen Grant, Claire Mahaffey, Sabena Blackbird, Erin McClymont, Rosalind Rickaby, Alex Poulton, and Victoria Peck. "Organic carbon isotopes of planktic foraminifera." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7047.

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2

Kelany, Abdel Rahman M., Sherif F. Farouk, Ahmed A. Kassem, and Mohamed E. Abuel Majd. "Sequence Stratigraphy and Paleobathymetry of the Lower-Middle Miocene Succession, Gulf of Suez, Egypt." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211674-ms.

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Abstract In the Gulf of Suez rift basin, the Miocene sequence is a significant hydrocarbon resource. An integration of the planktonic foraminifera, and benthic foraminiferal biofacies are data used to build a detailed and fine chronostratigraphic scheme for the lower part to middle part Miocene succession in the October Field, Gulf of Suez. The paleoecologic habits and paleobathymetry of benthic foraminiferal biofacies, as well as the planktic/benthic (P/B) ratios of the studied successions, are used to determine the paleoenvironmental conditions that are in effect during the deposition of the studied Miocene successions. Elphidium biofacies are representative of the inner shelf paleoenvironment, Nonion biofacies and Siphonina/Cibicides biofacies are representative of the middle shelf paleoenvironment, Bulimina and Uvigerina biofacies are representative of the paleoenvironment outer shelf. The paleoenvironmental interpretations and chronostratigraphic for data and the nature of stratigraphic relations are integrated to distinguish five depositional sequences in the studied section. These are two in the Aquitanian/Burdigalian, one in the Burdigalian-Langhian, one in the Langhian, and one sequence in the Serravallian ages. The sequence boundaries were marked by subaerial exposures and hiatuses. A detailed correlation between the distinguished sequence stratigraphic lower-middle Miocene frame and those established in and outside Egypt is attempted. The absolute time equivalents of the planktic foraminiferal zones are adjusted by comparison with the geologic time scale of Gradstein et al. 2022. This comparison points out a more or less compatible correlation, with a few deviations that may be related to tectonic events that led to the absence of some recorded depositional sequences.
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3

Kearns, Lorna, and Thomas H. G. Ezard. "IS POROSITY A FUNCTIONAL TRAIT IN PLANKTIC FORAMINIFERA?" In GSA Connects 2022 meeting in Denver, Colorado. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022am-379749.

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4

Kalia, Prabha. "Early Paleocene Planktic Foraminifers and Stratigraphy, Jaisalmer Basin, Rajasthan." In Proceedings of XXIII Indian Colloquium on Micropaleontalogy and Stratigraphy and International Symposium on Global Bioevents in Earth's History. Geological Society of India, 2015. http://dx.doi.org/10.17491/cgsi/2013/63307.

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5

Conde, Serena, Kaustubh Thirumalai, and Kaustubh Thirumalai. "HETEROGENEOUS PLANKTIC FORAMINIFERAL RESPONSE TO DEGLACIAL INDIAN MONSOON CHANGES." In GSA Connects 2022 meeting in Denver, Colorado. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022am-381554.

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6

Fehrenbacher, Jennifer S., M. Kelsey Lane, Theresa Fritz-Endres, and Haojia Ren. "GEOCHEMISTRY OF CULTURED AND PLANKTON TOW CAPTURED PLANKTIC FORAMINIFERA SUGGEST NON-SPINOSE SPECIES LIVE IN A PARTICULATE MICROHABITAT." In GSA 2020 Connects Online. Geological Society of America, 2020. http://dx.doi.org/10.1130/abs/2020am-356101.

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7

Richey, Julie N., Caitlin E. Reynolds, and Jennifer S. Fehrenbacher. "ENVIRONMENTAL CONTROLS ON BARIUM INCORPORATION INTO PLANKTIC FORAMINIFER, GLOBOROTALIA TRUNCATULINOIDES." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-305279.

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8

Albright, Brandon, and Kristen St. John. "PLANKTIC FORAMINIFERA BIOSTRATIGRAPHY OF CORE MD02-2555, GULF OF MEXICO." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-305942.

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9

Fehrenbacher, Jennifer. "Exploring controls on the geochemistry of non-spinose planktic foraminifera via culture experiments, plankton tow specimens, and micron-scale analyses." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7494.

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10

Beiranvand, Bijan, and Ebrahim Ghasemi Nejad. "Late Campanian to Paleocene Planktic Foraminiferal Biozonation for Izeh, the Zagros Basin, Iran." In GEO 2010. European Association of Geoscientists & Engineers, 2010. http://dx.doi.org/10.3997/2214-4609-pdb.248.374.

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Звіти організацій з теми "Planktic"

1

Banse, Karl. Plankton Production Biology. Fort Belvoir, VA: Defense Technical Information Center, September 2010. http://dx.doi.org/10.21236/ada541815.

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2

Banse, Karl. Plankton Production Biology. Fort Belvoir, VA: Defense Technical Information Center, September 2012. http://dx.doi.org/10.21236/ada573308.

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3

Banse, Karl. Plankton Production Biology. Fort Belvoir, VA: Defense Technical Information Center, September 2013. http://dx.doi.org/10.21236/ada599066.

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4

Banse, Karl. Plankton Production Biology. Fort Belvoir, VA: Defense Technical Information Center, September 2007. http://dx.doi.org/10.21236/ada604620.

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5

Donaghay, Percy L. Plankton Patch Feasibility Experiments. Fort Belvoir, VA: Defense Technical Information Center, September 2000. http://dx.doi.org/10.21236/ada609785.

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Donaghay, Percy L. Plankton Patch Feasibility Experiments. Fort Belvoir, VA: Defense Technical Information Center, September 1997. http://dx.doi.org/10.21236/ada627832.

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7

Donaghay, Percy L. Plankton Patch Feasibility Experiments. Fort Belvoir, VA: Defense Technical Information Center, September 2001. http://dx.doi.org/10.21236/ada628051.

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8

Donaghay, Percy L. Plankton Patch Feasibility Experiments. Fort Belvoir, VA: Defense Technical Information Center, September 1999. http://dx.doi.org/10.21236/ada629834.

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9

Adler, Robert. Superprocesses and Plankton Dynamics. Fort Belvoir, VA: Defense Technical Information Center, November 1997. http://dx.doi.org/10.21236/ada336941.

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10

Provenzale, A. Plankton Sinking and Turbulence. Fort Belvoir, VA: Defense Technical Information Center, July 2010. http://dx.doi.org/10.21236/ada557215.

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